Segment for a rehabilitation pipe, and pipe rehabilitation method

ABSTRACT

A segment for a rehabilitation pipe is formed of an inner surface plate having an inner circumferential surface, and side plates and end plates provided upright on a peripheral edge of the inner surface plate. The inner surface plate, the side plates, and the end plates are formed integrally from a plastic material, and a number of such segments are linked in circumferential and pipe-length directions to form the rehabilitation pipe. Each of the side plates is provided with at least one hole through which a linking member is inserted for linking the segments in the pipe-length direction, and is provided separately from the hole with an opening at an end in the vicinity of the end plate for a linking operation of the segments in the circumferential direction and for passing therethrough a filler material injected into a space between the existing pipe and the rehabilitation pipe.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a segment for a rehabilitation pipecomprising an inner surface plate constituting an inner circumferentialsurface, and side plates and end plates provided upright on peripheraledges of the inner surface plate, wherein the inner surface plate, theside plates, and the end plates are formed integrally from a plasticmaterial and the segments are linked in the circumferential directionand in the pipe-length direction to construct a rehabilitation pipeinside an existing pipe. The present invention also relates to a piperehabilitation method using the segments.

2. Description of the Related Art

In cases in which a sewage pipe or another pipeline buried undergroundhas deteriorated through aging, a pipe lining method has been proposedand practiced in which a lining is provided to the inner circumferentialsurface thereof to repair the pipeline without excavating it from theground.

In this pipe lining method, a pipe lining material made of a tubularresin absorbent material impregnated with an uncured thermosetting resinis everted and inserted into a pipeline using fluid pressure, and ispressed by fluid pressure against the inner peripheral wall of thepipeline. The lining material is then heated using a desired method tocure the thermosetting resin therein and form a plastic pipe, therebyrepairing the pipeline.

There is also known a lining method using segments each comprising aninner surface plate constituting an inner circumferential surface, sideplates and end plates provided upright on the peripheral edges of theinner surface plate, these plates being integrally formed from a plasticmaterial. The segments are linked in the circumferential direction toassemble short pipe units, which are then linked in the pipe-lengthdirection to construct a rehabilitation pipe inside an existing pipe(for example, JP-A 2005-264635). Such a pipe rehabilitation method isused for large-diameter existing pipes. In this method, after assemblinga rehabilitation pipe inside the existing pipe, grout or another fillermaterial is injected into a space between the existing pipe and therehabilitation pipe and hardened to construct a composite pipe.

SUMMARY OF THE INVENTION

In the rehabilitation pipe described in JP-A 2005-264635, an opening isprovided to the inner surface plate of the segment in the vicinity of anedge thereof in the circumferential direction in order to facilitatetightening of a bolt for linking the segments in the circumferentialdirection. After the segments are linked in the circumferentialdirection, the segments are linked in the pipe-length direction and therehabilitation pipe is installed in the existing pipe. If the opening isnot blocked in advance, the filler subsequently injected into the spacebetween the rehabilitation pipe and the existing pipe will flow into therehabilitation pipe through the opening. Therefore, a problem ispresented in that it is necessary to block the opening in the innersurface plate of every segment using a lid or another means after thesegments are linked in the circumferential direction in order to preventthe injected filler material from flowing into the rehabilitation pipethrough the opening. This makes the rehabilitation operation morecomplex. Also, in an instance in which the opening is blocked using alid, it is necessary that the lid and the inner circumferential surfaceof the segment form a uniform surface without any unevenness. This alsocomplicates the operation of linking the segments in the circumferentialdirection.

It is therefore an object of the present invention to provide a segmentfor a rehabilitation pipe that can be linked in the circumferentialdirection in a simple manner and that can save the amount of laborinvolved in the overall rehabilitation operation, and to provide a piperehabilitation method using the segments.

The present invention provides a segment for a rehabilitation pipecomprising an inner surface plate constituting an inner circumferentialsurface, and side plates and end plates provided upright on a peripheraledge of the inner surface plate. The inner surface plate, the sideplates, and the end plates are formed integrally from a plastic materialand the segments are linked in a circumferential direction and in apipe-length direction to install a segmental rehabilitation pipe insidean existing pipe. In the present invention, each of the side plates isprovided at an end in the vicinity of the end plate with an opening usedfor a linking operation of the segments in the circumferentialdirection.

The present invention also provides a pipe rehabilitation method forinstalling a rehabilitation pipe inside an existing pipe using a segmentthat comprises an inner surface plate constituting an innercircumferential surface, and side plates and end plates provided uprighton a peripheral edge of the inner surface plate, the inner surfaceplate, the side plates, and the end plates being formed integrally froma plastic material. In the method, each of the side plates is providedat an end in the vicinity of the end plate with an opening used for alinking operation of the segments in the circumferential direction, andthe end plates of the segments are brought into contact with each other.A linking member is inserted into the opening provided to the side plateto sequentially link the segments in the circumferential direction,thereby forming a pipe unit. The thus formed pipe units are sequentiallylinked in the pipe-length direction to install a segmentalrehabilitation pipe inside the existing pipe. The filler material isinjected into the space between the existing pipe and the rehabilitationpipe to construct a composite pipe.

According to the present invention, the side plate is provided at an endin the vicinity of the end plate with an opening used for a linkingoperation of the segments in the circumferential direction. Therefore,it is possible to insert a bolt, a nut, or another linking memberthrough the opening and readily link the segments in the circumferentialdirection.

The opening is formed in the side plate, instead of the inner surfaceplate as according to conventional techniques. Therefore, the fillermaterial injected between the rehabilitation pipe and the existing pipeafter the rehabilitation pipe is assembled in the existing pipe will notflow through the opening into the rehabilitation pipe. Therefore, theneed for closing the opening formed in the side plates is obviated, andthe rehabilitation operation can be made more efficient.

Also, the opening formed in the side plate is formed so that the fillermaterial injected into the space between the existing pipe and therehabilitation pipe flows in or out through the opening. Therefore, thefiller material can be injected into the space in a smoother andspeedier manner, making the filling operation more efficient.

Further features of the invention, its nature and various advantageswill be more apparent from the accompanying drawings and followingdetailed description of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing the structure of a segment used inassembling the rehabilitation pipe;

FIG. 2a is a front view of a side plate of a segment;

FIG. 2b is a cross-sectional view along line B-B in FIG. 2 a;

FIG. 2c is a detailed view of an end plate of the segment viewed fromthe direction of line A-A in FIG. 2 a;

FIG. 3a is a front view of an inner plate of the segment;

FIG. 3b is a cross-sectional view along line C-C in FIG. 3 a;

FIG. 4 is a front view of another inner plate of the segment;

FIG. 5a is a cross-sectional view showing the segments linked in thecircumferential direction with a bolt and a nut;

FIG. 5b is a cross-sectional view showing the segments linked in thecircumferential direction;

FIG. 5c is a front view showing the segments linked in thecircumferential direction;

FIG. 6 is a perspective view showing a state in which the segments arelinked in the circumferential direction to assemble a pipe unit;

FIG. 7 is an illustrative view showing a state in which the segments ofthe pipe units are linked in the pipe-length direction using linkingmembers;

FIG. 8 is an illustrative view showing a state in which the pipe unitsare linked and the rehabilitation pipe is installed in the existingpipe; and

FIG. 9 is a perspective view showing a state in which the pipe units arelinked and the rehabilitation pipe is installed in the existing pipe.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will now be described with references toembodiments illustrated in the accompanying drawings. The presentinvention is suitable for rehabilitating or repairing sewage pipes,water supply pipes, tunnels, agricultural irrigation channels, and otherexisting large-diameter pipes. In the present embodiment, therehabilitation pipes are described as having a circular cross-sectionprofile orthogonal to the pipe-length direction. However, it shall beapparent that the present invention can be applied to a rehabilitationpipe having a square or another non-circular cross-section. Also, inaddition to structures in which the cross-section profile is closed as apipe, a structure having a horseshoe-shaped, semi-circular, U-shaped, oranother cross-section profile in which one side is open can also beconsidered to be a pipe, and the present invention can also be appliedthereto.

In the present specifications, the pipe-length direction refers to thedirection indicated by arrow X extending in the longitudinal directionof a pipe unit 10 in FIG. 6, the radial direction refers to thedirection indicated by the radial arrow R pointing towards the centeraxis of the pipe unit 10, and the circumferential direction refers tothe direction of the circumference of the circle forming the pipe unit10.

FIG. 1 shows the structure of a segment 1 for pipe rehabilitation(hereafter simply referred to as “segment”), which represents anassembly unit member of a rehabilitation pipe for rehabilitating anexisting pipe. The segment 1 is an integrally formed block-shaped membermade from a plastic material, comprising an inner surface plate 101constituting an inner circumferential surface of the rehabilitationpipe, side plates 102, 103 provided vertically upright on both sidesextending in the circumferential direction of the inner surface plate101, and end plates 104, 105 provided vertically upright on both endsextending in the pipe-length direction of the inner surface plate 101.

In the present embodiment, the segment 1 has a shape that is curved asan arc representing a predetermined angle that equally divides thecircumference, e.g., a 60° arc that divides the circumference intosixths. However, the segment is not limited to that having an arc or afan shape. The segment may be shaped as, e.g., a cuboid or a shape thatis bent so as to have a curved right angle depending on thecross-section profile or the size of the existing pipe or the locationof the existing pipe to be repaired.

A plurality (four in the present embodiment) of inner plates 106, 107having a shape similar to that of the side plates are provided uprightat equal intervals and parallel to the side plates 102, 103 on the uppersurface of the inner surface plate 101 and on the inside relative to theside plates 102, 103 in order to reinforce the mechanical strength ofthe segment 1. One or both of the inner plates 106, 107 can be omittedif the segment 1 has sufficient strength.

The inner surface plate 101, the side plates 102, 103, the end plates104, 105, and the inner plates 106, 107 are all made from an identicaltransparent, semi-transparent or opaque plastic material, and areintegrally formed using a known molding technique.

FIG. 2a is a detailed view of the side plates 102, 103, and FIG. 2b is across-section view along the line B-B in FIG. 2a . The followingdescriptions are given in relation to the side plate 102, but the sideplate 103 has a configuration similar to that of the side plate 102.

The side plate 102 is an arc-shaped thin-plate member, and an uppersection 102 d has a smaller plate thickness than that of a lower section102 e. This is in order to form a gap on the upper part of the two sideplates 102, 103 when one segment is liked to another segment adjacent inthe pipe-length direction, and to guide and accommodate earth and othermaterial entering from the exterior.

A plurality of holes 102 a for admitting insertion of a liking memberfor linking the segment 1 in the pipe-length direction are provided atequal intervals along the circumference on the lower section 102 e ofthe side plate 102. The holes 102 a in the side plate 102 and holes 103a in the side plate 103 are located at coinciding positions along thecircumferential direction, allowing the liking member to be insertedthrough the holes 102 a and 103 a in the side plates 102 and 103.

An opening 102 b, used for a linking operation of the segments in thecircumferential direction, is provided to the side plate 102 in thevicinity of both ends in the circumferential direction, i.e., at bothends in the vicinity of the end plates 104,105. Each of the openings 102b has a rectangular shape in which corners are chamfered. A lower edgeof the opening 102 b is proximate to a lower edge of the side plate 102,and an upper edge of the opening 102 b is somewhat lower than an upperedge of the side plate 102. When the segments are connected in thecircumferential direction, a bolt, a nut, or another linking member is,e.g., positioned or tightened through the opening 102 b (see also FIG.5c ).

The opening 102 b is configured so that a filler material injected intoa space between the existing pipe and the segmental rehabilitation pipecan flow in or out through the opening 102 b, and so that duringinjection, the filler material can pass through the opening 102 b in asmooth and speedy manner. It is also possible to provide the openings102 b, 103 b to the vicinity of the end plate 104 only or to thevicinity of the end plate 105 only.

Notches 102 c for allowing the filler material to flow in or out andpass therethrough are provided to an upper section of the side plate102. The notches 102 c have a half-moon shape in which the upper end isopen. The notches 102 c are positioned in the circumferential directionso as to be displaced from the positions of the holes 102 a in thecircumferential direction. More specifically, a notch 102 c is providedbetween the hole 102 a nearest to the end plates 104, 105 and the nexthole 102 a, and then provided every two holes 102 a. Thus, a total ofseven notches 102 c are provided to the side plate 102.

FIG. 2c is a detailed view of the end plate 105 as viewed from line A-Ain FIG. 2a . The following descriptions are given in relation to the endplate 105, but the end plate 104 has a configuration similar to that ofthe end plate 105.

The end plate 105 is a rectangular thin-plate member arranged betweenthe side plate 102 and the side plate 103. The height of the end plate105 from the outer surface of the inner surface plate 101 is slightlylower than that of the side plates 102, 103. Circular insertion holes105 a for admitting insertion of a bolt or another linking member forlinking the segment 1 in the circumferential direction are provided onthe end plate 105 between the side plate 102 and an inner plate 106,between the inner plate 106 and an inner plate 107, between the twoinner plates 107, between the inner plate 107 and an inner plate 106,and between the inner plate 106 and the side plate 103.

A concave section 101 a and a convex section 101 b are provided to theinner surface plate 101 along the entire length of the circumferentialdirection on one end thereof in the pipe-length direction (right end inFIG. 2c ). A convex section 101 c and a concave section 101 d areprovided on the other end so that the convex/concave relationship isinverted. As a result, when the segments are linked in the pipe-lengthdirection, the concave and convex sections of segments that are adjacentin the pipe-length direction engage with each other and fulfill thefunction of guiding or positioning of the segments. This facilitates theoperation of linking the segments in the pipe-length direction.

A rectangular opening 105 d for allowing the filler material to flow inor out and pass therethrough is provided to both sides of the innerplates 107, both sides of the inner plates 106, and the inside of theside plates 102, 103 at the lower end of the end plate 105.

A convex section 105 c is provided on the end plate 105 at a position atwhich it intersects the inner plate 107, and is fitted into a concavesection 104 c provided to the corresponding position on the end plate104 that is adjacent in the circumferential direction (see also FIG. 5b).

FIG. 3a is a detailed view of the inner plate 106, and FIG. 3b is across-sectional view along the line C-C in FIG. 3a . Each of the innerplates 106 is a thin-plate member having a profile substantiallyidentical to the side plates 102, 103. Circular holes 106 a foradmitting insertion of linking members for linking the segments in thepipe-length direction are provided at equal intervals to a lower sectionof the inner plate 106. The positions of the holes 106 a in thecircumferential direction coincide with those of the holes 102 a of theside plate 102. As shown in FIG. 3b , the diameter of each of the holes106 a increases from the vicinity of the center of the plate thicknessof the inner plate 106 towards the outside (i.e., the side towards theside plate).

Notches 106 b for allowing the filler material to flow in or out andpass therethrough are provided to the upper section of the inner plate106. The notches 106 b have a half-moon shape in which the upper end isopen. The positions of the notches 106 b are different in thecircumferential direction from those of the holes 102 a, 106 a. Morespecifically, a notch 106 b is provided further towards the end platethan the hole 106 a nearest to the end plates 104, 105, and are providedevery two holes 106 a. Thus, a total of eight notches 106 b areprovided. Therefore, the positions of the notches 106 b in thecircumferential direction are displaced from those of the notches 102 cof the side plate 102 by an amount equivalent to the intervals betweenthe holes 106 a in the circumferential direction. The notches 106 b andthe notches 102 c are thus in a staggered arrangement when the segmentis viewed from above. This also applies to the notches 103 c provided tothe side plate 103 for passing the filler material, and to the notches106 b formed on the inner plate 106 adjacent to the side plate 103.

FIG. 4 is a detailed view of the inner plate 107. The inner plate 107 isa thin-plate member having a profile that substantially coincides withthe side plates 102, 103. A plurality of notches 107 a is provided fromthe vicinity of the lower end towards the upper end of the inner plate107. The positions of the notches 107 a in the circumferential directioncoincide at the lower section thereof with those of the holes 102 a inthe side plate 102 and the holes 106 a in the inner plate 106. The notch107 a at the center of the segment 1 is perpendicular to the innersurface plate 101, and the other notches 107 a are oriented so as to beparallel to the notch 107 a in the center. Such an arrangementfacilitates removal from the mold when the segment is integrally formed.

FIGS. 5a, 5b, and 5c show a method for linking the segments 1 in thecircumferential direction. Two segments 1, 1 are held so that the endplate 105 of one of the segments and the end plate 104 of the othersegment are in contact with each other. A wrench or another tool, or atechnician's finger, is inserted from the opening 102 b in the sideplate 102 of the segment, and a bolt 6 is inserted into the insertionholes 104 a, 105 a. A nut 7 is then threadedly engaged to the bolt 6,thereby tightening both end plates 104, 105 and linking the two segments1, 1 in the circumferential direction. The concave section 104 c andconvex section 105 c that fit into the concave section 104 c are formedon the end plate 104 and the end plate 105 at a position at which theyintersect with the inner plate 107.

A concave section 104 e and a convex section 104 f are formed along theentire length in the pipe-length direction on a lower end of the endplate 104. A convex section 105 f and a concave section 105 e that fitwith the concave section 104 e and the convex section 104 f are formedalong the entire length in the pipe-length direction on a lower end ofthe end plate 105. Such an arrangement facilitates the task ofpositioning the two segments 1 and bringing the two segments in closecontact with each other when the segments are linked in thecircumferential direction. Also, applying a sealing material (not shown)to the fitting section makes it possible to enhance the water-tightnessof the linking section. Bolting as described above is performed in twolocations, i.e., between the side plate 102 and the adjacent inner plate106, and between the side plate 103 and the adjacent inner plate 106. Inan instance in which the linking in two locations as described aboveresults in insufficient linking strength, a linking member is alsopositioned in other insertion holes 104 a, 105 a, from above thesegment, between the inner plates 106, 107 to strengthen the linking inthe circumferential direction.

In FIG. 5a , one bolt/nut set is used per location. However, in aninstance in which the end plates 104, 105 have a large height because ofsegments used for large-diameter existing pipes, the segments can belinked in the circumferential direction using two or more bolt/nut setsper location.

The segments are thus linked in the circumferential direction throughthe openings 102 b, 103 b provided to the side plates 102, 103. When thesegments are linked in the pipe-length direction so that the opening 102b of the segment is in alignment with the opening 103 b of the adjacentsegment and both the segments come in close contact with each other,each set of the openings 102 b, 103 b forms a single integral opening.Therefore, when the filler material is injected into the spacing betweenthe existing pipe and the rehabilitation pipe after installation of therehabilitation pipe, the filler flows in or out through the integratedopenings 102 b, 103 b without flowing downwards towards the interior ofthe rehabilitation pipe. Therefore, there is no need to block theopenings 102 b, 103 b, and linking in the circumferential direction canbe performed in a simpler manner compared to an instance in which anopening is provided to the inner surface plate 101.

By sequentially linking the segments 1 in the circumferential directionaround the full circumference, it is possible to assemble a closedring-shaped short pipe assembly 10 (hereafter referred to as “pipeunit”) having a predetermined small length in the pipe-length directionX as shown in FIG. 6. The pipe unit 10 has a shape that can be obtainedwhen a circular pipe is sliced at a predetermined width Dperpendicularly to the pipe-length direction X. The outside diameter ofthe pipe unit 10 is slightly smaller than the inside diameter of theexisting pipe to be rehabilitated. The segment 1 corresponds to a memberobtained by dividing the pipe unit 10 into a plurality of (preferablyequal) portions along a cutting surface parallel to the radial directionR.

In FIG. 6, the inner surface plate 101, the side plates 102, 103, andthe end plates 104, 105, which are the principal structural members ofthe segment 1, are shown. In order to prevent the drawing from becomingcomplicated, the inner plates 106, 107 and other reinforcementstructures are not shown.

Each of the segments in the pipe unit 10 of such description is linkedto a segment of another pipe unit using a linking member (tighteningmember) 11 and a nut 12 as shown in FIG. 7 for extension in thepipe-length direction.

The nut 12 is passed through a hole 102 a in the side plate 102 of onesegment 1 a and brought into contact with the first inner plate 106,i.e., the inner plate 106 positioned nearest to the side plate 102. Abolt 13 is threaded into the nut 12, and the nut 12 is tightened againstthe inner plate 106 and fixed against it.

The length of the nut 12 in the pipe-length direction is slightlygreater than the spacing between the side plate 102 and the inner plate106, and is such that the nut 12 protrudes outwards from the side plate102 of the segment 1 a when positioned as above. The amount ofprotrusion is equivalent to or greater than the thickness of the sideplate 103 of the other segment 1 b. Therefore, the nut 12 is passedthrough the hole 103 a in the side plate 103 of the other segment 1 b,and the two segments 1 a, 1 b are placed against each other.

In this state, a linking member 11 is passed through a hole 102 a in theside plate 102, a hole 106 a in the inner plate 106, and a notch 107 ain the inner plate 107 of the segment 1 b, and a threaded section 11 bof the linking member 11 is threaded into the nut 12 to link the linkingmember 11 and the nut 12. The linking member 11 is further threaded intothe nut 12 until a flange section 14 a of a head section 14 pressesagainst the leftmost inner plate 106 of the segment 1 b to tighten andfix the two segments 1 a, 1 b.

A plurality of the nuts 12 are fixed along the circumferential directionto each segment, the nuts 12 being fixed to every second hole 102 a, orat less regular intervals, depending on the required strength. Thesegments are linked in the pipe-length direction with the nut positionsin each segment being displaced in the circumferential directionrelative to the nut positions in the segment adjacent to the segment inquestion. For example, in the example shown in FIG. 7, the positions ofthe nuts 12 in the segment 1 a in the center is displaced relative tothe positions of the nuts 12 in the segment is adjacent to the rightside of the segment 1 a by an amount corresponding to the intervalsbetween the holes 102 a in the side plate 102 as viewed in thecircumferential direction.

Thus, the segments of the pipe unit are linked in the pipe-lengthdirection to the segments of another pipe unit, whereby it is possibleto link the pipe units in the pipe-length direction to a desired length,and to create a rehabilitation pipe comprising the pipe units or thesegments.

A description will now be given for a method for rehabilitating anexisting pipe using the segments configured as described above.

First, as shown in FIG. 8, the segment 1 is carried through a manhole 20into an existing pipe 21, and as shown in FIGS. 5 and 6, the segmentsare sequentially linked in the circumferential direction to assemble thepipe unit 10.

Next, the pipe units 10 are sequentially linked in the pipe-lengthdirection via the linking members 11 using the method shown in FIG. 7,and as shown in FIGS. 8 and 9, the rehabilitation pipe 40 is installedin the existing pipe 21. In FIGS. 8 and 9, the linking members 11 andsimilar elements are not shown, and the segments are shown in asimplified manner.

In FIGS. 7 through 9, the segments or the pipe units are linked in thepipe-length direction such that the segment and the segment adjacentthereto are offset to each other in the circumferential direction andthe end plates of both the segments are out of alignment in thepipe-length direction. Such an arrangement makes it possible toautomatically block the openings 102 b, 103 b of the side plates 102,103 by the side plates of the adjacent segment. Therefore, there is noneed to block the openings 102 b, 103 b, and linking in thecircumferential direction can be performed in a simpler manner.

If the diameter of the rehabilitation pipe is large, the segments 1 thathave been carried in can be transported to the location of actualinstallation, and the segments are linked in the circumferentialdirection and the pipe-length direction at this location. In such aninstance, there may be instances in which the gap between the outside ofthe segments and the existing pipe is narrow when linking the segmentsin the circumferential direction. This may obstruct the mounting ofbolt-and-nut sets from the outside of the segment; the benefit ofproviding the side plates with openings for linking the segments in thecircumferential direction is particularly high.

Next, as shown in FIG. 9, a grout material or another filler material 30is injected into a space S between the rehabilitation pipe 40 and theexisting pipe 21, and the filler material is hardened. Both end sectionsof the space S are blocked using a resin pate, mortar, or anothersealing agent. For injection of the filler material, an injection holeis formed in, e.g., the inner surface plate 101, and the filler material30 is injected therefrom. Injection is performed until the fillermaterial 30 has reached the entirety of the rehabilitation pipe and hasstarted to flow out from the side plates of segments on both ends in thepipe-length direction. During injection, the filler material 30 don'tflow out from the openings 102 b, 103 b of the side plates 102, 103 intothe inside of the rehabilitation pipe 40. Such openings, therefore,improve the efficiency of the linking operation and the injectionoperation.

Since the notches 102 c, 103 c, 106 b are respectively provided to theside plates 102, 103 and the inner plate 106 of the segment 1, thefiller material can flow smoothly in the pipe-length direction even ifthe space S is small or if an obstacle is present in the space S. Also,since the notches 102 c, 103 c formed in the side plate 102 or 103 andthe notches 106 b formed in the adjacent inner plate 106 are staggeredwhen the segment is viewed from above (outside), the filler material isinjected in a zigzag shape, thus allowing the filler material to beinjected in a uniform manner.

The height of the end plates 104, 105 is smaller than the height of theside plates 102, 103 and the inner plates 106, 107, and there is asignificant gap between the upper end of the end plates 104, 105 and theexisting pipe 21; therefore, the filler material can also flow smoothlyin the circumferential direction. The holes 104 d, 105 d provided to thelower section of the end plates 104, 105 not only allow the fillermaterial to flow in or flow out and pass through, but also function as apassage for air between the existing pipe 21 and the inner surface plate101 pushed out when injecting the filler material, therefore allowingthe filler material to flow in an even smoother manner.

The injected filler material 30 allows the existing pipe 21 and therehabilitation pipe 40 to be solidly bound when it is hardened, and itbecomes possible to create a composite pipe comprising the existingpipe, the filler material, and the rehabilitation pipe.

What is claimed is:
 1. A segment for a rehabilitation pipe, the segmentcomprising: an inner surface plate having an inner circumferentialsurface, and side plates and end plates provided upright on a peripheraledge of the inner surface plate; wherein the inner surface plate, theside plates, and the end plates are formed integrally from a plasticmaterial and the segments are linked in a circumferential direction andin a pipe-length direction to install a segmental rehabilitation pipeinside an existing pipe; wherein each of the side plates is providedwith at least one hole through which a linking member is inserted forlinking the segments in the pipe-length direction, and is providedseparately from the hole with an opening at an end in the vicinity ofthe end plate for a linking operation of the segments in thecircumferential direction and for passing therethrough a filler materialinjected into a space between the existing pipe and the rehabilitationpipe, and wherein each of the end plates has at least one hole throughwhich another linking member is inserted for linking the segments in thecircumferential direction, the openings of the side plates beingconfigured so that when the segments are connected in thecircumferential direction, the another linking member is insertedthrough the at least one hole of each of the end plates and positionedand/or tightened through the openings of the side plates.
 2. The segmentfor a rehabilitation pipe according to claim 1, wherein for each of theside plates, the opening is provided to each of both ends of the sideplate.
 3. The segment for a rehabilitation pipe according to claim 1,wherein for each of the side plates, a lower edge of the opening isproximate to a lower edge of the side plate, and an upper edge of theopening is lower than an upper edge of the side plate.
 4. A pipe unitfor a rehabilitation pipe used to rehabilitate an existing pipe, thepipe unit comprising a plurality of segments according to claim 1mutually linked in a circumferential direction of the pipe unit.
 5. Arehabilitation pipe for rehabilitating an existing pipe, therehabilitating pipe comprising: a plurality of pipe units according toclaim 4 mutually coupled together in a longitudinal direction of theexisting pipe to assemble the rehabilitating pipe.
 6. A piperehabilitation method for installing a rehabilitation pipe inside anexisting pipe, the method comprising: providing a plurality of segmentseach comprised of an inner surface plate having an inner circumferentialsurface, and side plates and end plates provided upright on a peripheraledge of the inner surface plate, each of the side plates being providedwith at least one hole through which a linking member is inserted forlinking the segments in a pipe-length direction, and being providedseparately from the hole with an opening at an end in the vicinity ofthe end plate for a linking operation of the segments in thecircumferential direction and for passing therethrough a filler materialinjected into a space between the existing pipe and the rehabilitationpipe, the inner surface plate, the side plates, an the end plates beingformed integrally from a plastic material; bringing the end plates ofthe segments into contact with each other; inserting a linking memberinto through the openings provided to the side plates of each pair ofadjacent segments whose end plates have been brought into contact witheach other to sequentially link the segments in the circumferentialdirection, thereby forming a pipe unit; sequentially linking the pipeunits in the pipe-length direction by inserting another linking memberinto the holes provided to the side plates of each pair of the adjacentsegments to install a segmental rehabilitation pipe inside the existingpipe; and injecting a filler material into a space between the existingpipe and the rehabilitation pipe so that the filler material passesthrough the openings provided to the side plates of each pair of theadjacent segments.
 7. The pipe rehabilitation method according to claim6, wherein for each of the side plates of each segment, the opening isprovided to each of both ends of the side plate.
 8. The piperehabilitation method according to claim 6, wherein each of the endplates of each of the provided plurality of segments has at least onehole; wherein the end plates of the segments are brought into contactwith each other so that the holes of the end plates are aligned with oneanother; and wherein the linking member is inserted through the openingsprovided to the side plates and positioned relative to the aligned holesof the end plates to link the segments in the circumferential direction.9. The pipe rehabilitation method according to claim 6, wherein for eachof the side plates of each of the provided plurality of segments, alower edge of the opening substantially coincides with a lower edge ofthe side plate, and an upper edge of the opening is lower than an upperedge of the side plate.
 10. In a pipe unit for a rehabilitation pipeused to rehabilitate an existing pipe, the pipe unit being formed of aplurality of segments mutually coupled together in a circumferentialdirection of the pipe unit, each of the segments comprising: an innersurface plate having a pair of opposite peripheral edges extending in apipe-length direction of the rehabilitation pipe and a pair of oppositeperipheral edges extending in the circumferential direction of the pipeunit; a pair of end plates provided upright on the respective peripheraledges of the inner surface plate extending in the pipe-length direction,each of the end plates having at least one hole through which a linkingmember is inserted for linking the segments together in thecircumferential direction; and a pair of side plates provided upright onthe respective peripheral edges of the inner surface plate extending inthe circumferential direction, each of the side plates having an openingthat is provided at an end thereof in the vicinity of one of the endplates and that is configured to provide access therethrough to thelinking member when positioning and inserting the linking member throughthe holes of the end plates to sequentially link the segments togetherin the circumferential direction to form the pipe unit.
 11. The pipeunit according to claim 10, wherein each of the side plates is providedwith at least one hole different from the opening and through whichanother linking member is inserted for linking the segments in thepipe-length direction.
 12. The pipe unit according to claim 11, whereinfor each of the side plates, the opening is provided to each of bothends of the side plate and the at least one hole comprises a pluralityof holes extending between the openings at both ends of the side plate.13. The pipe unit according to claim 10, wherein for each of the sideplates, the opening is provided to each of both ends of the side. 14.The pipe unit according to claim 10, wherein for each of the segments,the inner surface plate, the side plates and the end plates are formedintegrally from a plastic material.
 15. The pipe unit according to claim10, wherein for each of the side plates of each of the segments, a loweredge of the opening substantially coincides with a lower edge of theside plate, and an upper edge of the opening is lower than an upper edgeof the side plate.
 16. The pipe unit according to claim 10, wherein foreach of the side plates of each of the segments, the opening isconfigured for passing therethrough a filler material that is injectedinto a space between the existing pipe and the rehabilitation pipe. 17.A rehabilitation pipe for rehabilitating an existing pipe, therehabilitating pipe comprising: a plurality of pipe units according toclaim 10 mutually coupled together in a pipe-length direction of theexisting pipe to assemble the rehabilitating pipe.